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//Portions Copyright [2018-2019] [Payara Foundation and/or affiliates]
package org.glassfish.admin.amx.util.stringifier;

import com.sun.enterprise.security.auth.realm.certificate.CertificateRealm;
import org.glassfish.admin.amx.util.StringUtil;

import javax.security.auth.x500.X500Principal;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.cert.X509Certificate;

/**
 * Stringifies an {@link X509Certificate}.
 */
public final class X509CertificateStringifier implements Stringifier {

    public final static X509CertificateStringifier DEFAULT = new X509CertificateStringifier();

    private static byte[] getFingerprint(byte[] signature, String alg) {
        byte[] result = null;

        try {
            final MessageDigest md = MessageDigest.getInstance(alg);

            result = md.digest(signature);
        } catch (NoSuchAlgorithmException e) {
            result = signature;
            e.printStackTrace();
        }

        return (result);
    }

    /**
     * Static variant when direct call will suffice.
     */
    public static String stringify(final X509Certificate cert) {
        final StringBuilder buf = new StringBuilder();
        final String NL = "\n";

        buf.append("Issuer: ").append(cert.getIssuerDN().getName()).append(NL);
        buf.append("Issued to: ").append(cert.getSubjectDN().getName()).append(NL);
        buf.append("Version: ").append(cert.getVersion()).append(NL);
        buf.append("Not valid before: ").append(cert.getNotBefore()).append(NL);
        buf.append("Not valid after: ").append(cert.getNotAfter()).append(NL);
        buf.append("Serial number: ").append(cert.getSerialNumber()).append(NL);
        buf.append("Signature algorithm: ").append(cert.getSigAlgName()).append(NL);
        buf.append("Signature algorithm OID: ").append(cert.getSigAlgOID()).append(NL);

        buf.append("Signature fingerprint (MD5): ");
        byte[] fingerprint = getFingerprint(cert.getSignature(), "MD5");
        buf.append(StringUtil.toHexString(fingerprint, ":")).append(NL);

        buf.append("Signature fingerprint (SHA1): ");
        fingerprint = getFingerprint(cert.getSignature(), "SHA1");
        buf.append(StringUtil.toHexString(fingerprint, ":")).append(NL);

        return (buf.toString());
    }

    @Override
    public String stringify(Object object) {
        return (stringify((X509Certificate) object));
    }
}
